The present invention relates to a control system for a motor, and more particularly to a control system for applying phase current to the motor.
A switched reluctance motor (SRM) is a type of electric motor that converts reluctance torque into mechanical power. SRMs are relatively tolerant to faults (e.g., no braking torque under a short circuit fault and no shoot-through fault in an inverter circuit). SRMs do not include magnets, and therefore do not produce a cogging torque (cogging torque is created by an interaction between permanent magnets of a rotor and stator slots). Moreover, SRMs also have a relatively high operational temperature, concentrated motor windings, and a relatively simple and rugged construction. However, SRMs also produce a relatively high torque ripple as well as acoustic noise. Torque ripple is typically defined as a periodic increase or decrease in output torque of an output shaft of the SRM.
Electric motors utilized in electric power steering (EPS) applications are generally required to produce relatively low torque ripple and low acoustic noise. Thus, the torque ripple and the acoustic noise produced by an SRM may need to be reduced before being used in an EPS application.